the critical self talk is normal. you should watch seth godin's talk "quieting the lizard brain" https://vimeo.com/5895898

i just had a similar conversation, but it dealt with music instead of code. this person felt they couldn't improvise/ create.

the problem isn't with their abilities, it's that they were taught to follow instructions - like the notes on sheet music. jazz musicians play off what they hear instead. however, they first internalized the rules and then forgot them.

you've already got the rules down - so the next step is to "forget" them.

a time constraint like going to a hackathon is a good place to start. you're pushing yourself to create in a short amount of time.

here, you'll focus on shipping...drowning out the critical voice in your head.

it's much like a muscle. the more you build and struggle through, the stronger you'll get.